Jump to content

Instability


panzerd18
 Share

Recommended Posts

So after flying it, finally, what I'm see is that is it rather torque sensitive, and that the wildest hunting is either when the plane is below 150 mph IAS or the turbo is surging.

 

I'm wondering if the feedback loop on the turbo is fully tuned yet?

 

I've also noticed that if you fuel the plane it leaves the main tank partially empty and fills the aux tank which will mess up the center of gravity and should make the plane super twitchy in all the controls.

Link to comment
Share on other sites

Well, Idk and I am pulling my hair out with it.

I just cannot stop the thing from going into an uncontrollable left hand spin!

I’m in the training missions and doing exactly what the voice says, but as soon as I try to climb it all goes tits up! The rudder is trimmed to the centre of the bubble, but no matter how much aileron trim I put in it still pulls wildly left and eventually I just have to accept my fate.

Has anyone else had this? Has anyone else found a solution, because afaik this thing just seems too unstable to be flyable. I know I’ve got a lot to learn but this one is ridiculous! Please help!

Cheers

Rick

Link to comment
Share on other sites

Well, Idk and I am pulling my hair out with it.

I just cannot stop the thing from going into an uncontrollable left hand spin!

I’m in the training missions and doing exactly what the voice says, but as soon as I try to climb it all goes tits up! The rudder is trimmed to the centre of the bubble, but no matter how much aileron trim I put in it still pulls wildly left and eventually I just have to accept my fate.

Has anyone else had this? Has anyone else found a solution, because afaik this thing just seems too unstable to be flyable. I know I’ve got a lot to learn but this one is ridiculous! Please help!

Cheers

Rick

 

If possible, please record a video and upload to youtube, it would be easier to help you this way. Also, please press "right control + enter" to check your joystick input (might be good to check your joystick axis calibration).

 

In fact it's not easy to fly like the P-51, however, the bird is not unstable that much.

 

I found that "dancing" a bit with the rudder for like a second when it starts to become unstable helps a lot for me.

A-10C / AJS-37 / AV-8B / BF-109 / KA-50 / F-14 / F-16C / F-5E / F/A-18C / FC3 / JF-17 / F-86 / M-2000C / MiG-21bis / P-51D / Spitfire LF Mk. IX / UH-1H Huey

Link to comment
Share on other sites

"Fly the engine"

The 51 has a notoriously wicked roll if power was slammed on especially on a go around.

I watched a real 109's throttle range and it was only a few inches forward to go from idle to all you could handle.

The Jug carry a lot of inertia so you have to be smooth on the rudder with power changes or she can/will swing on you.

I am more concerned about the trim and elev. Maybe some PIREP from a actual test flight could confirm/deny that FM area.

Link to comment
Share on other sites

https://ntrs.nasa.gov/search.jsp?R=19930083857

 

This is full NACA report about longitudinal stability. I used a picture from it to clarify that the plane is unstable at power-on modes.

 

Just in case - neutral point is the CoG position the plane is longitudinally neutral under the certain conditions.

1002935893_29Cx_ind1.thumb.png.13cdbf6d6013e2ac631f3c420e709164.png

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

Yeah,it does seem to 'porpoise' about when diving,even when all trimmed out,trying to keep the nose still when strafing or dive bombing is quite a feat.

 

I've been throttling back anyway when diving,as the jug dives really quickly,a well known historical character of the jug,because of it's enormous weight,and obviously the fm is taking this into consideration,so this is very realistic.

 

However it's keeping that nose balanced in this dive,that's the issue,it's almost like it's buffeting in the turbulence when diving.

 

My two pennies worth anyway,and this would be my only gripe,it's a superb module that's for sure.Given that it's only been released a few days I'm sure the devs will tweak it in the near future,so I'm quietly confident this will be addressed.

Chillblast Fusion Cirrus 2 FS Pc/Intel Core i7-7700K Kaby Lake CPU/Gigabyte Nvidia GTX 1070 G1 8GB/Seagate 2TB FireCuda SSHD/16GB DDR4 2133MHz Memory/Asus STRIX Z270F Gaming Motherboard/Corsair Hydro Series H80i GT Liquid Cooler/TM Warthog with Sahaj 15cm Extension/MFG Crosswind V2 Pedals/Saitek Cessna Trim Wheel & Throttle Quadrants/TrackiR4/Windows 10 Home/Sense of humour,I find it comes in handy !

 

 

Link to comment
Share on other sites

To me, the P-47 is a giant leap forward for DCS in recognizing the existence of engine torque in all flight regimes.

 

It actually feels somewhat like there is a high powered engine swinging a massive prop instead of flying like a jet with a prop graphic on it.

 

Dont know how about you, but i can feel it in every DCS's warbirds so far.Non of them act like a jet plane.

Windows 11, I9 9900KF @5.0, Gigabyte Z390 Aorus PRO, Ram 32 GB G.skill, Palit Gamerock OC 3090, Hotas Warthog, Thrustmaster Pendular Pedals, OLED 48" 120Hz.

Link to comment
Share on other sites

Yeah,it does seem to 'porpoise' about when diving,even when all trimmed out,trying to keep the nose still when strafing or dive bombing is quite a feat.

 

I've been throttling back anyway when diving,as the jug dives really quickly,a well known historical character of the jug,because of it's enormous weight,and obviously the fm is taking this into consideration,so this is very realistic.

 

However it's keeping that nose balanced in this dive,that's the issue,it's almost like it's buffeting in the turbulence when diving.

 

My two pennies worth anyway,and this would be my only gripe,it's a superb module that's for sure.Given that it's only been released a few days I'm sure the devs will tweak it in the near future,so I'm quietly confident this will be addressed.

 

Make sure you close the cowl before a dive. This is a known cause of buffeting.

Link to comment
Share on other sites

As others have discussed, and picking up on effects of engine management by content folks (links in this thread) - Yes, the torque of the engine, the effect of the dorsal fin in this model, and engine management will cause the nose to yaw about a bit depending on a multitude of settings, and how hard you are pulling on the stick.

 

Which is absolutely WONDERFUL, I love it; however, some ways I have found to mitigate it.

 

I have mapped rudder trim to my Throttle HOTAS (Thrustmaster) and will trim accordingly to offset roll induced by engine power, torque, boost settings. It is very dynamic, you will do this a lot. I also set very small curve changes to create a lower rate of change off the initial axis movement of the stick for Pitch and Roll.

 

If you have rudder pedals, if you find that constantly trimming the Rudder is laborious and tricky, especially in combat, offset inertia rolls with rudder input, this will keep the front from wobbling when in a turning fight. It won't completely eliminate it, but it will reduce it.

 

Also, from another excellent vid, pulling back on the stick hard will cause oscillation, sometimes just let off the pressure a bit, and the nose oscillation will dampen down.

 

My 2 cents FWIW - many fighters cannot get away from her in climbing nose up energy fights, such a wonderful quirky airplane!!!

 

:thumbup:

Pointy end hurt! Fire burn!!
JTF-191 25th Draggins - Hawg Main. Black Shark 2, A10C, A10CII, F-16, F/A-18, F-86, Mig-15, Mig-19, Mig-21, P-51, F-15, Su-27, Su-33, Mig-29, FW-190 Dora, Anton, BF 109, Mossie, Normandy, Caucasus, NTTR, Persian Gulf, Channel, Syria, Marianas, WWII Assets, CA. (WWII backer picked aircraft ME-262, P-47D).

Link to comment
Share on other sites

Make sure you close the cowl before a dive. This is a known cause of buffeting.

 

Thanks for the tip Paganus,I will definitely check I've got it closed from now on thumbup.gif

Chillblast Fusion Cirrus 2 FS Pc/Intel Core i7-7700K Kaby Lake CPU/Gigabyte Nvidia GTX 1070 G1 8GB/Seagate 2TB FireCuda SSHD/16GB DDR4 2133MHz Memory/Asus STRIX Z270F Gaming Motherboard/Corsair Hydro Series H80i GT Liquid Cooler/TM Warthog with Sahaj 15cm Extension/MFG Crosswind V2 Pedals/Saitek Cessna Trim Wheel & Throttle Quadrants/TrackiR4/Windows 10 Home/Sense of humour,I find it comes in handy !

 

 

Link to comment
Share on other sites

Thanks for this Yo-Yo, great document, fascinating read. Just affirms what we are seeing when flying under different power modes.

 

Much appreciated!

Pointy end hurt! Fire burn!!
JTF-191 25th Draggins - Hawg Main. Black Shark 2, A10C, A10CII, F-16, F/A-18, F-86, Mig-15, Mig-19, Mig-21, P-51, F-15, Su-27, Su-33, Mig-29, FW-190 Dora, Anton, BF 109, Mossie, Normandy, Caucasus, NTTR, Persian Gulf, Channel, Syria, Marianas, WWII Assets, CA. (WWII backer picked aircraft ME-262, P-47D).

Link to comment
Share on other sites

https://ntrs.nasa.gov/search.jsp?R=19930083857

 

This is full NACA report about longitudinal stability. I used a picture from it to clarify that the plane is unstable at power-on modes.

 

Just in case - neutral point is the CoG position the plane is longitudinally neutral under the certain conditions.

 

And if the front tank is underloaded, the rear tank is full, and people are draining from the main tank, that's just going to make everything worse isn't it?

 

I can't seem to find it in the D-30 manuals, but I did notice in the 01-65BC-1 manual (January 1943) in the Pilot's Operating Instructions that there is an explicit prohibition on carrying fuel in the rear tank during Instrument Flights, Practice Landings, acrobatics, practice combat maneuvers, or high speed dives.

 

Once the fuel loads are forward biased rather than rear biased should we expect to see less of this when running at lower fuel loads?

Link to comment
Share on other sites

And if the front tank is underloaded, the rear tank is full, and people are draining from the main tank, that's just going to make everything worse isn't it?

 

I can't seem to find it in the D-30 manuals, but I did notice in the 01-65BC-1 manual (January 1943) in the Pilot's Operating Instructions that there is an explicit prohibition on carrying fuel in the rear tank during Instrument Flights, Practice Landings, acrobatics, practice combat maneuvers, or high speed dives.

 

Once the fuel loads are forward biased rather than rear biased should we expect to see less of this when running at lower fuel loads?

 

You guys know what is the percentage to make sure that only main tank has gas?

A-10C / AJS-37 / AV-8B / BF-109 / KA-50 / F-14 / F-16C / F-5E / F/A-18C / FC3 / JF-17 / F-86 / M-2000C / MiG-21bis / P-51D / Spitfire LF Mk. IX / UH-1H Huey

Link to comment
Share on other sites

Most of if not all missions that came with p47 has that only main tank with gas, want to say 67% but not in the pit to check:thumbup:

 

Thank you very much enduro.

A-10C / AJS-37 / AV-8B / BF-109 / KA-50 / F-14 / F-16C / F-5E / F/A-18C / FC3 / JF-17 / F-86 / M-2000C / MiG-21bis / P-51D / Spitfire LF Mk. IX / UH-1H Huey

Link to comment
Share on other sites

Dont know how about you, but i can feel it in every DCS's warbirds so far.Non of them act like a jet plane.

 

You can easily prove it to yourself.

 

The first requirement is a basic understanding of physics.

 

When a force is acting on a body there must be an opposing force equal in magnitude to maintain equilibrium.

 

If the magnitude of the force changes the magnitude of the opposing force must also vary in order to maintain the desired equilibrium.

 

https://courses.lumenlearning.com/boundless-physics/chapter/conditions-for-equilibrium/

 

There are easily demonstrated examples of how these basic principles are violated in DCS prop FM's

 

The P-47 seems to be a step forward in this regard and I am hopeful what is learned will be applied to existing and future flight models.

475th Fighter Group Discord https://discord.gg/xkKsApD

 

 

 

EDsignaturefleet.jpg

Link to comment
Share on other sites

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...